From b81612c292fff0c466c567aa3c297e70e1f4dded Mon Sep 17 00:00:00 2001
From: Nuno Campos <nuno@boringbits.io>
Date: Sun, 21 Jul 2024 12:16:37 -0700
Subject: [PATCH 1/2] cli: Fix crash when subprocess has a very long
 stdout/stderr line

---
 libs/cli/langgraph_cli/exec.py             | 31 ++++++++++++++++++----
 libs/cli/tests/unit_tests/test_config.json |  2 +-
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/libs/cli/langgraph_cli/exec.py b/libs/cli/langgraph_cli/exec.py
index b32eb44c3..3c9557bbe 100644
--- a/libs/cli/langgraph_cli/exec.py
+++ b/libs/cli/langgraph_cli/exec.py
@@ -131,21 +131,42 @@ async def monitor_stream(
     if collect:
         ba = bytearray()
 
-    def handle(line: bytes):
+    def handle(line: bytes, overrun: bool):
         nonlocal on_line
         nonlocal display
 
+        if display:
+            sys.stdout.buffer.write(line)
+        if overrun:
+            return
         if collect:
             ba.extend(line)
-        if display:
-            sys.stdout.write(line.decode())
         if on_line:
             if on_line(line.decode()):
                 on_line = None
                 display = True
 
-    async for line in stream:
-        await asyncio.to_thread(handle, line)
+    """Adpated from asyncio.StreamReader.readline() to handle LimitOverrunError."""
+    sep = b"\n"
+    seplen = len(sep)
+    while True:
+        try:
+            line = await stream.readuntil(sep)
+            overrun = False
+        except asyncio.IncompleteReadError as e:
+            line = e.partial
+            overrun = False
+        except asyncio.LimitOverrunError as e:
+            if stream._buffer.startswith(sep, e.consumed):
+                line = stream._buffer[: e.consumed + seplen]
+            else:
+                line = stream._buffer.clear()
+            overrun = True
+            stream._maybe_resume_transport()
+        await asyncio.to_thread(handle, line, overrun)
+        if line == b"":
+            break
+
     if collect:
         return ba
     else:
diff --git a/libs/cli/tests/unit_tests/test_config.json b/libs/cli/tests/unit_tests/test_config.json
index 8062b1719..642b30ded 100644
--- a/libs/cli/tests/unit_tests/test_config.json
+++ b/libs/cli/tests/unit_tests/test_config.json
@@ -2,7 +2,7 @@
     "python_version": "3.12",
     "pip_config_file": "pipconfig.txt",
     "dockerfile_lines": [
-        "ARG meow"
+        "ARG meow=woof"
     ],
     "dependencies": [
         "langchain_openai",

From 34407d9de135733d8cbac37f7244212bfb54872e Mon Sep 17 00:00:00 2001
From: Nuno Campos <nuno@boringbits.io>
Date: Sun, 21 Jul 2024 12:19:19 -0700
Subject: [PATCH 2/2] Update exec.py

---
 libs/cli/langgraph_cli/exec.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libs/cli/langgraph_cli/exec.py b/libs/cli/langgraph_cli/exec.py
index 3c9557bbe..d6282ccfe 100644
--- a/libs/cli/langgraph_cli/exec.py
+++ b/libs/cli/langgraph_cli/exec.py
@@ -146,7 +146,7 @@ async def monitor_stream(
                 on_line = None
                 display = True
 
-    """Adpated from asyncio.StreamReader.readline() to handle LimitOverrunError."""
+    """Adapted from asyncio.StreamReader.readline() to handle LimitOverrunError."""
     sep = b"\n"
     seplen = len(sep)
     while True: